The present invention relates to recovering from a fault in the connectivity of a data processing system to a local area network (LAN), and more particularity relates to providing recovery of connectivity to a LAN in the event of the failure of one of a group of LAN adapters which connect a data processing system to a LAN.
High availability requirements for networks are usually the most stringent within an Internet environment. These requirements are for the most part met through a high degree of redundancy and complexity. The LAN environment is no exception. Servers are physically isolated from clients using separate LANs and multiple LAN attachments creating an extra layer of complexity. This is all due to the make up of the LAN protocols which impose a unique MAC_address restriction to each attached station on a given LAN.
For SNA traffic, bridges with MAC_address filtering are used. With TCP/IP traffic, an IP router and a dynamic routing protocol (i.e., RIP or OSPF) are used to mask MAC_addresses by directing traffic via virtual IP_addresses. Both solutions are designed to provide a single access point and nondisruptive connectivity.
U.S. Pat. No. 5,341,363, issued Aug. 23, 1994, to Hirasawa for COMPUTER SYSTEM CAPABLE OF DISCONNECTING ITSELF FROM A LAN, discloses a logical connecting/disconnecting section for logically disconnecting a computer system from the LAN in response to the detection of the failure at a failure detection section.
U.S. Pat. No. 5,455, 932, issued Oct. 3, 1995, to Major et al. for FAULT TOLERANT COMPUTER SYSTEM, discloses a method and apparatus for providing a fault-tolerant backup system such that if there is a failure of a primary processing system, a replicated system can take over without interruption.
U.S. Pat. No. 5,473,771, issued Dec. 5, 1995, to Burd et al. for FAULT-TOLERANT PROCESSING SYSTEM ARCHITECTURE, discloses a fault-tolerant call-processing adjunct processor comprising a redundant, duplicated, service unit provisioning and maintenance processor, a duplicated LAN connected to both service units, and a plurality of served units, each connected to both LANs.
U.S. Pat. No. 5,781,715, issued Jul. 14, 1998, to Sheu for FAULT-TOLERANT BRIDGE/ROUTER WITH A DISTRIBUTED SWITCH-OVER MECHANISM, and U.S. Pat. No. 5,848,227, issued Dec. 8, 1998, to Sheu for METHOD OF PROVIDING FAULT TOLERANCE AND SWITCH-OVER DISTRIBUTION IN A BRIDGE/ROUTER, disclose a fault-tolerant router for providing the prevention of packet loss so that a source station does not have to resend lost packets blocked due to a failed processing element and provide transparency to end stations so that the packet recovery is independent of the networking protocols implemented.
U.S. Pat. No. 5,781,716, issued Jul. 14, 1998, to Hemphill et al. for FAULT TOLERANT MULTIPLE NETWORK SERVERS, discloses a fault tolerant multiple network server system in which multiple servers concurrently act as back-up servers for each other even while they are providing their own server services to the system, rather than having an unused server monitoring for failure of a primary server and taking over control.
U.S. Pat. No. 5,835,481, issued Nov. 10, 1998, to Akyol et al. for FAULT TOLERANT LANE SYSTEM, discloses an ATM network having a set of LAN emulation connection servers which connect with each other to determine which servers are operational and to automatically select an operational master server. Servers which lose their connection are directed to the proper server by a table stored in the ATM switch.
PCT Application WO 92/18931, published Oct. 29, 1992, for Eastman Kodak Company for FAULT TOLERANT NETWORK FILE SYSTEM, discloses a fault tolerant network fileserver system including a plurality of nodes connected to a network communication link. A primary fileserver node stores files from a plurality of the nodes and a backup fileserver node stores copies of files from the primary fileserver. The primary and backup fileservers are connected to a dual ported memory for communicating information between the fileservers.
PCT application WO 99/33227, published Jul. 1, 1999, for Holontech Corporation for CROSS-PLATFORM SERVER CLUSTERING USING A NETWORK FLOW SWITCH, discloses a network flow switch for connecting a pool of IP routers to a cluster of IP servers sharing a single IP address without requiring translation of the IP address. All IP servers have the same IP address.
IBM Technical Disclosure Bulletin, Vol. 35 No. 5 October 1992, pages 95-96, for HARDWARE FAULT TOLERANT 3745 COMMUNICATION CONTROLLER xe2x80x94A MAJOR STEP TO A NON-DISRUPTIVE NETWORK SWITCHING, discloses a fault tolerance on the 3745 engine having a mode wherein the content of the two CCUs will be exactly identical and the backup one may continue the task if the active one fails.
IBM Technical Disclosure Bulletin, Vol. 35 No. 7 December 1992, pages 300-303, for FAULT-TOLERANT ARCHITECTURE FOR COMMUNICATION ADAPTERS AND SYSTEMS, discloses fault-tolerant adapters with multiple network interface modules to overcome failures at the interface level and with software memory management support to overcome failures of the hardware memory manager. Redundant adapters are used to overcome permanent failures of an adapter""s processor subsystem.
IBM Technical Disclosure Bulletin, Vol. 38 No. 02 February 1995, pages 29-31, for LOCAL AREA NETWORK BACK-UP SERVICE, discloses a hardware and software implementation to provide a back-up server for LAN operations as used with personal computers. The back-up server is designed to monitor the activities of a domain controller and assumes the identity of the domain controller when a failure is detected.
It is a primary object of the present invention to provide for the nondisruptive takeover of a failing or failed LAN adapter by a backup adapter in a data processing system connected to a LAN.
It is another object of the present invention to provide for an apparatus which provides for the nondisruptive takeover of a failing or failed LAN adapter by a backup adapter in a data processing system connected to a LAN.
It is another object of the present invention to provide for a program product for providing for the nondisruptive takeover of a failing or failed LAN adapter by a backup adapter in a data processing system connected to a LAN.
It is another object of the present invention to provide for placing the MAC_address of a failed LAN adapter into a backup LAN adapter upon the detection of the failure of the failed adapter such that the backup LAN adapter may nondisruptively take over for the failed adapter.